The "PDF" you are looking for is most likely Sombra (Book 3 of the Silencio saga) or Silence (Book 3 of Hush Hush). We will focus on the former.
Yes. The Silencio saga is a completed trilogy: Silencio → Espectro → Sombra . No Book 4 has been announced. Silencio Saga Hush Hush 3 Pdf